Atopic dermatitis is an allergic disease caused by a defect of a stratum corneum which is a protective wall located in the outermost part of the skin which is caused by hereditary, environmental, or immunological factors and is exacerbated in arid climates. Many people are afflicted by the atopic dermatitis, specifically 0.5-1% of the total population. In cases of minors, 5-10% of children are afflicted by the atopic dermatitis. 50% of patients can recover by their second birthday, and 25% can recover by puberty. However, 25% never recover and continue to suffer from atopic dermatitis into adulthood.
The main symptoms of atopic dermatitis are severe pruritus, xeroderma, eruption or oozing of the skin, boils, scale like skin (scaly skin), etc.
The pathogenesis of atopic dermatitis is not completely understood, but genetic factors are attributed to most cases of atopic dermatitis, and the pathogenesis is related to immune response. It has been shown that atopic dermatitis can be caused by a combination of dry skin, skin that is prone to itching more than the average person, infections caused by bacteria virus fungi, etc., and emotional and environmental factors.
Specifically, an antibody (IgE) produced by a mast cell during the body's process of naturally eliminating a material which causes a rash to form when in contact or invading the body causes a hypersensitive reaction when this same material invades the body again producing a histamine which causes the atopic dermatitis. The mast cell is distributed widely throughout organs such as, the skin, respiratory organs, mucosa of the gastrointestinal tract, circum of lymphatic duct, brain, and is known as the cell that causes diverse inflammation and allergic reactions. The histamine released from the mast cell causes inflammation and immediate allergic reaction by inducing vasodilation, smooth muscle-contraction of the gastrointestinal and/or bronchial tract, secretion of glandular cells, exacerbation of the reactions, etc., and serves as an intermediary for diverse biological effects such as secretion of mucus and local protein.
Pharmacotherapies, such as steroids, anti-histamines, antibiotics are usually prescribed for atopic dermatitis. The steroid agent (adrenal cortical hormone agent) can act as an anti-inflammatory and immuno-suppressant and has positive effect in treating the disease, but if used over a long period of time, side effects such as skin-weakening, symptom of systemic hormone, toxicity can result. Currently, uses of immune-suppression agents and novel anti-histamine agents have been studied for treating atopic dermatitis. However, anti-histamine agents cannot completely suppress the allergic reaction since other chemical transmitters in addition to the histamine can induce the allergic reaction. The mast cell releases other chemical transmitters such as leukotriene C4 and leukotriene B4 in addition to the histamine. Leukotriene C4 contracts the smooth muscle of bronchus like the histamine, and leukotriene B4 causes chronic inflammation by inducing neutrophil and eosinophil and injures neighboring cells.
Thus, a novel composition for the effective treatment of atopic dermatitis without the side-effects is required.
Bamboo belongs to the Poaceae family. There are about 280 known species of bamboo all over the world, and about 70 species grow naturally or are cultivated in Korea. There are 11 representative kinds of Bamboo; Phyllostachys nigra, Phyllostachys bambusoides (Cedrela sinesis), Phyllostachys edulis (Phyllostachys pubescen), Phyllostachys nigra for. Punctata, Sasa borealis var. gracilis, Arundinaria simonii, Sasa borealis var. chiisanensis, Sasa borealis, Sasa albo-marginata, Pseudosasa japonica, etc. Among them, Phyllostachys bambusoides (Cedrela sinesis), Phyllostachys nigra and Phyllostachys edulis are cultivated. According to Dongeui-Bogam, Compendium of Materia Medica and the divine Farmer's Materia Medica, Bamboo is effective in treating palsy and hypertension, and was used to treat pneumonia and bronchitis to bring down fever, loosen phlegm and as a coolant. Recently, it has been reported that Bamboo has been used to treat hypertension, atherosclerosis and cardiovascular disease. Bamboo is also known to have anti-oxidant effect which is effective in the prevention of cancer and aging. Also, phytochemicals such as organic acid, dietary fiber, tannin, benzofuran within the plant are expected to contribute to preventing diseases of the circulatory system.
The conventional studies for bioactive compounds focusing on antimicrobial activity have been reported mostly in Korean and Japan. Japanese researchers discovered the 2,6-dimethylbenzoquinone and benzoic acid which are antimicrobial compounds in the leaf of Bamboo, and Korean Patent No. 10-0465113 discloses the effects of bamboo extract in improving blood circulation and preventing inflammation. Japanese Patent Publication H09-278662 discloses fats and oils which have anti-allergic effect contains the Bamboo extract obtained by using the soxhlet method using ether as a solvent, and WO 2002/07745 discloses that Bamboo extract obtained by using water has antipruritic effect which is effective in the treatment of atopic dermatitis.
Scutellaria has bioactive and pharmacological properties and has been used in oriental medicine for treating fevers and allergies. It acts by dilating blood vessels and brings down blood pressure, and inhibits atherosclerosis. Bicalin contained in Scutellaria is a kind of flavonoid which is effective to sedate or stop bleeding by suppressing the permeability of capillaries. Also, bicalin inhibits the release of chemical transmitters by strengthening the mast cell membrane and so can do anti-allergic action. Specifically, it is known that the pharmacological properties of Scutellaria are improving infections caused by allergies, inhibiting increased vascular permeability and alleviating inflammatory discharge of blood and congestion by strong anti-inflammatory effect, and these pharmacological properties are derived from bicalin. Bicalin is hydrolyzed to baicalein and glucuronic acid. Baicalein acts as a diuretic and glucuronic acid acts as deintoxicant. Korean Patent Publication No. 1996-0003725 discloses a therapeutic agent comprising of the flavonoid ingredient of Scutellaria. Korean Patent Publication No. 1996-0040370 discloses a composition for the prevention and treatment of alcohol disorder comprising of Scutellaria extract and flavone glycoside. Korean Patent Publication No. 2002-0031608 discloses a Scutellaria extract that has positive antimicrobial effect, and the process for preparing the extract and the pharmaceutical composition of the extract. Korean Patent No. 10-0522579 discloses a mixture extract of Scutellaria and Omija (Schizandra chinensia Baillon) which has anti-stress effect.
The above properties of Bamboo or Scutellaria have been known, but there has not been reported any therapeutic effect for atopic dermatitis using the mixture composition comprising of Bamboo extract and Scutellaria extract.
The inventors of the present invention have studied a novel compound for the treatment of atopic dermatitis. As a result, they discovered and confirmed that the mixture composition comprising Bamboo extract and Scutellaria extract can strongly inhibit the release of histamine and leukotrien without any side-effects and has positive therapeutic effect on atopic dermatitis, to complete the present invention.